Various interfaces have been developed in which an image is displayed in a view of a user wearing a head mounted display as one of input interfaces, and the user applies an operation to the image so that the user can perform input.
Patent Document 1 discloses a technique in which an image displayed in a view of a user by a head mounted display is operated by using a mobile terminal of the user. Specifically, among images displayed in the view of the user, the user holds the mobile terminal so that a touch panel of the mobile terminal is superimposed on an image desired to be operated, and the image displayed on the head mounted display is operated by applying an operation to the touch panel.
Patent Document 2 discloses a technique of performing input by using a virtual keyboard displayed on a head mounted display. Patent Document 2 discloses a technique in which the virtual keyboard is fixed to an object on a real space, and thus a position of the virtual keyboard is not changed even if the head of a person wearing the head mounted display is moved.
Patent Document 3 discloses a technique in which an annotation is virtually added to an object on a real space which is seen through a head mounted display by using a tablet terminal cooperating with the head mounted display.
Patent Document 4 discloses a technique in which a menu screen is displayed on the palm of a user, or the menu screen is changed according to a gesture of the palm (for example, a gesture of opening the palm).